Apparatus and system for cutting fiber-cement materials and methods of operation and use

ABSTRACT

Apparatus and methods of processing fiber-cement workpieces to form fiber-cement shake panels. One embodiment of such a method comprises positioning a cured fiber-cement workpiece over an anvil plate having at least one slot and driving a cutting blade along a straight, vertical path to pass a cutting edge of the cutting blade through the workpiece. The process can optionally include coating the fiber-cement panels before installing the fiber-cements panels on a wall.

TECHNICAL FIELD

This technology generally relates to cutting machines and knife/dieapparatus for cutting fiber-cement materials to form, for example,shake-panel siding used on or in houses and other structures.

BACKGROUND

The exterior surfaces of houses and other structures are often protectedby exterior siding products made from wood, vinyl, aluminum, bricks,stucco, fiber-cement and other materials. Wood and fiber-cement siding(FCS) products, for example, are generally planks, panels or shakes thatare attached to plywood or composite walls. Although wood sidingproducts are popular, wood siding can become unsightly or even defectivebecause wood generally rots, warps or cracks over time. Wood sidingproducts are also highly flammable and subject to insect damage. FCS isan excellent alternative building material because it is nonflammable,weatherproof, relatively inexpensive to manufacture, and does not usethe limited remaining cedar or fir resources. FCS also does not rot, noris it consumed by insects.

FIG. 1 shows a prior art fiber-cement shake-panel 20 having a length Lextending along a longitudinal direction and widths W₁ and W₂ extendingalong a direction transverse relative to the length L. The shake-panel20 has side edges 23 separated from each other by the longitudinaldirection, a top edge 22 extending along the longitudinal dimensionbetween the upper ends of the side edges 23, and a bottom edge 24extending along the longitudinal dimension between the bottom ends ofthe side edges 23. The top and bottom edges 22 and 24 are typicallysubstantially parallel to each other and separated by a constantwidthwise dimension or varying widthwise dimensions (e.g., W₁ or W₂).The shake-panel also includes a web portion 32 and a plurality of shakesections 30 a and 30 b of different lengths L_(s1) and L_(s2) projectingfrom the web portion 32. The individual shake sections 30 a and 30 b areseparated by slots 28 such that the shake sections 30 a and 30 b havevarious widths corresponding to the distance between adjacent slots 28.

FIG. 2 illustrates an early prior art cutting machine 34 suitable forforming the shake-panel 20 shown in FIG. 1. Referring to FIG. 2, thecutting machine 34 includes a frame 36, a plurality of cutting stations35 a-35 d, and a plurality of rollers 58 for supporting and advancing asheet of fiber-cement to be cut. The cutting stations 35 b and 35 c areconfigured to cut the slots 28 shown in the shake panel 20 of FIG. 1.The cutting station 35 b includes a slot cutting assembly 53 having ablade holder 54, a plurality of cutting blades 56 attached to the bladeholder 54, and an actuator 60 for driving the blade holder 54 alongrotational path R₁. Each cutting blade 56 is configured to cut anindividual slot 28 shown in the shake panel 20. The blade holder 54 ispivotally connected to the frame 36 such that the actuator 60 moves theblade holder 54 along the rotational path R₁ between a cutting position(lowered position not shown in FIG. 2) and a retracted position (raisedposition shown in FIG. 2). The cutting station 35 c includes a cuttingassembly 63 having a blade holder 62 pivotally connected to the frame, aplurality of slot cutting blades 64 attached to the blade holder 62, andan actuator 60 coupled to the blade holder 62 and the frame 36 to rotatethe cutting assembly 63 along another rotational path R₂.

FIG. 3 illustrates a cutting assembly 63 a used in a later cuttingmachine described in U.S. patent application Ser. No. 11/371,452 filedon Mar. 8, 2006, which is incorporated herein by reference in itsentirety. The cutting assembly 63 a includes a blade holder 62 a, aplurality of cutting blades 64 a attached to the blade holder 62 a, anda lower anvil 70 with a plurality of slots 72 configured to receiverespective cutting blades 64 a. In operation, a fiber-cement workpiece(not shown) is gripped between rollers 58 a and drive belts 59 that movethe workpiece along a path P until the workpiece is positioned at adesired location between the cutting blades 64 a and slots 72. Anactuator (not shown in FIG. 3) rotates the workpiece holder 62 adownwardly as indicated by arrow R so that the cutting blades 64 a passthrough the fiber-cement workpiece and into corresponding slots 72. Therollers 58 a and/or the belts 59 a then drive the workpiece along thepath P to withdraw the workpiece from the cutting blade 64 a, and thenthe actuator rotates the workpiece holder 62 a upwardly into theposition illustrated in FIG. 3.

PacTool International, Ltd. (PacTool), the assignee of the presentinvention, developed the cutting machines shown in FIGS. 2 and 3.Although the existing cutting machines illustrated in FIGS. 2 and 3 aresuitable for forming the shake-panel 20 illustrated in FIG. 1, theyrequired a significant amount of maintenance that increased theoperating cost. For example, the shape of the cutting blades 64 a andthe rotational motion of the blade holder 62 a required a significantamount of force to drive the cutting blades through the fiber-cementworkpiece. This generally caused a sudden fracture in the fiber-cementworkpiece that would in turn transmit significant impact forces to thelower plate 70, the blade holder 62 a and the frame 36. The impactforces were so great that welded connections between members of theframe 36 cracked and broke apart, and other parts of the machine wouldwear quickly. Therefore, PacTool sought to improve the longevity of thecutting machine.

In addition to the high operational costs of the existing cuttingmachines, the fiber-cement industry is moving toward pre-paintedshake-panel products in which the shake-panels are painted or stained ata manufacturing site before they are shipped to a distributor andinstalled. The shake-panels are painted or stained in a manner in whichparticles or dust remaining on the cut shake-panels can foul the paintand/or the painting equipment. This can increase maintenance costs anddowntime for the painting equipment and reduce the quality of thefinished coat of paint. The cutting blades 56, 64 and 64 a illustratedin FIGS. 2 and 3 produce good quality edges along the slots withoutcreating nearly as much dust as a rotating abrasive disc, but theseblades nonetheless produce a small amount of dust that sticks to theshake-panels and subsequently fouls the painting equipment used topre-paint the shake-panels. Therefore, PacTool International also soughtto develop an improved cutting machine that could produce fiber-cementshake-panels suitable for pre-painting operations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a prior art fiber-cement shake-panel.

FIG. 2 is a side view of a prior art cutting machine for forming theshake-panel of FIG. 1 from cured fiber-cement panels and/or planks.

FIG. 3 is an isometric view of a prior art slot cutting assembly forforming slots in cured fiber-cement planks or panels.

FIG. 4A is an isometric view of a cutting blade or knife for cuttingslots in cured fiber-cement panels and/or planks in the manufacturing offiber-cement shake-panels in accordance with an embodiment of thedisclosure.

FIG. 4B is a side view of the cutting blade of FIG. 4A and an anvilplate of a fiber-cement cutting machine in accordance with an embodimentof the disclosure.

FIG. 4C is an end view of the cutting blade and anvil plate shown inFIG. 4B.

FIGS. 4D-4G are side views of cutting blades in accordance with otherembodiments of the technology.

FIG. 5 is an isometric view of a cutting machine for, formingfiber-cement shake-panels in accordance with an embodiment of thedisclosure.

FIG. 6 is an isometric view showing a portion of the cutting machine ofFIG. 5 in more detail.

DETAILED DESCRIPTION

The following disclosure describes cutting machines and methods forcutting cured fiber-cement materials to form shake-panels or otherfiber-cement products. Many specific details of certain embodiments areset forth in the following description and in FIGS. 4A-6 to provide athorough understanding of such embodiments. One skilled in the art,however, will understand that the invention may have additionalembodiments, or that the invention may be practiced without several ofthe details described below. In the figures and description that follow,like elements and features are identified by like reference numerals.Additionally, the sizes and relative positions of elements in thedrawings may not necessarily be drawn to scale. For example, unlessotherwise expressly described in the text, the shapes, angles ordimensions of various elements are not drawn to scale, and some of theseelements are arbitrarily enlarged to improve the legibility of thedrawings. Further, unless expressly stated in the text, the particularshapes of the elements as drawn are not intended to convey anyinformation regarding the actual shape of the particular elements, andhave been selected for ease and recognition throughout the figures.

Reference throughout this specification to “one example,” “an example,”“one embodiment,” or “an embodiment” means that a particular feature,structure, or characteristic described in connection with the example orembodiment is included in at least one example of the presenttechnology. Thus, occurrences of the phrases “in one example,” “in anexample,” “one embodiment,” or “an embodiment” in various placesthroughout this specification are not necessarily all referring to thesame example or embodiment. Furthermore, the particular features,structures, routines, steps, or characteristics may be combined in anysuitable manner in one or more examples or embodiments of thetechnology. The headings provided herein are for convenience only andare not intended to limit or interpret the scope or meaning of theclaimed technology.

FIG. 4A is an isometric view of a cutting blade 100 in accordance withan embodiment of the technology. In this embodiment, the cutting blade100 includes a head 102 having holes 103 a and slots 103 b configured toreversibly attach the blade 100 to a blade mount as explained in moredetail below with reference to FIG. 5. The cutting blade 100 furtherincludes a channel 104 and a shank 106. The channel 104 is thinner thanthe shank 106 so that the blade 100 does not contact the workpiece whenthe blade 100 is in a lowered position. The shank 106 further includesan inclined edge 107 that extends at an angle α relative to an axisparallel to a cutting path S. The cutting blade 100 can optionallyinclude a hardened cutting element 108 either attached to or integralwith the shank 106. The cutting element 108 has a cutting edge 109inclined at the angle α and extending at the angle α all the way from afirst end 111 to a second end 112. The cutting element 108 can also havea piercing portion 115, such as a sharp tip or edge, at the lowermostextent of the cutting edge 109 and sidewalls 114. In other embodiments,the cutting edge 109 can be at the inclined edge of the shank 106, andthus the cutting edge 109 can have sidewalls defined by either thesidewalls of the cutting element 108 or the sidewalls of the shank 106depending on which of these features initially engages the workpiece W.

FIGS. 4B and 4C are side and end views, respectively, of the cuttingblade 100, an anvil plate 200, and a fiber-cement workpiece 250. FIGS.4A and 4B further illustrate the operation of the cutting blade 100 toform a slot 252 (FIG. 4C) in the fiber-cement workpiece 250 by movingthe cutting blade 100 along a straight cutting path S between a raisedposition and a lowered position. Referring to FIG. 4B, the blade 100 isin the raised position above the anvil plate 200 and aligned with a slot210 in the anvil plate 200. The slot 210 includes a first end wall 211having a first clearance C₁ relative to the first end 111 of the cuttingelement 108 (e.g., the first end of the cutting edges 109) and a secondend wall 212 having a clearance C₂ relative to the second end 112 of thecutting element 108 (e.g., the second end of the cutting edges 109).Referring to FIG. 4C, the slot 210 in the anvil plate 200 can furtherinclude sidewalls 213 having a clearance C₃ relative to sidewalls 113 ofthe shank 106 and/or sidewalls 114 of the cutting element 108.

In operation, a fiber-cement workpiece 250 is positioned under the blade100 and over the slot 210 when the blade 100 is in the raised positionshown in FIG. 4B. An actuator (not shown in FIGS. 4A and 4B) drives theblade 100 downward so that the piercing portion 115 of the cuttingelement 108 pierces the fiber-cement workpiece 250 and the cutting edge109 slices through the workpiece along the longitudinal dimension of theslot 210 to form the slot 252 in the workpiece W. Referring to FIG. 4C,the blade 100 moves downwardly along the straight cutting path S untilthe channel 104 is aligned with workpiece 250. The workpiece 250 canthen be moved in a direction D_(L) along the longitudinal dimension ofthe slot 210 until the workpiece 250 clears the blade 100. The blade 100is then raised along the straight path S to the raised positionillustrated in FIG. 4B to cut another workpiece. The channel 104 enablesthe workpiece W to be removed from the cutting area and the blade 100 tobe raised to the raised position without passing the shank 106 orcutting element 108 upwardly through the slot 252 formed in theworkpiece W. This eliminates delamination that could otherwise be causedby moving the cutting element 108 or shank 106 upwardly through the slot252.

In a specific embodiment of the blade 100 illustrated in FIGS. 4A-C, theangle α is from approximately 83.5° to approximately 85°. Although thisangle is relatively shallow with respect to the surface of the workpiece250, it produced a much cleaner cut with far fewer cracks along the cutslot 252 compared to a test blade having an angle α of 78°. Using anangle α of approximately 83.5° to approximately 85° also produced lessdust compared to blades with lower angles (i.e., steeper inclinerelative to the surface of the workpiece 250). The embodiment of theblade 100 having an angle α of approximately 83.5° to approximately 85°is accordingly well-suited for cutting slots in fiber-cement workpiecesto form shake-panels that are prepainted at a manufacturing facilitybefore being shipped to a distributor.

A specific embodiment of the blade 100 and the anvil plate 200 shown inFIGS. 4A-C has end clearances C₁ and/or C₂ of approximately 0.005-0.015inch and side clearances C₃ on each side of approximately 0.008-0.020inch. The end clearances C₁ and C₂ are preferably 0.010 inch for curedfiber-cement workpieces that have a low moisture content and a nominalthickness of 0.25 inch. The side clearances C₃ between the sidewalls 114of the cutting element 108 are preferably 0.015-0.018 inch, and inparticular 0.017 inch, for cutting a cured fiber-cement workpiece havinga low moisture content and a nominal thickness of 0.25 inch. The endclearance of 0.010 inch and the side clearance of 0.17 inch provideexcellent edge quality along the slot 252 formed in a cured fiber-cementworkpiece with a nominal thickness of 0.25 inch that further enhancesthe appearance and reduces the amount of dust. Even a modest differencein the side clearance C₃ to 0.020 inch causes a significant degradationof edge quality along the slot 252 that may render the shake-panels withsuch slots unsuitable for prepainting.

FIGS. 4D-4G illustrate additional embodiments of cutting blades 100. Asopposed to the cutting edge 109 extending at the angle α all the wayfrom the first end 111 to the second end 112 as shown in FIGS. 4A-4C,other embodiments of the cutting edge 109 can be curved and or extend ata different angle for a portion of its length. For example, the cuttingedge 109 can have a single curve of either a single radius or moregenerally a compound radius (shown in FIG. 4D), or the cutting edge 109can extend at a first angle from the first end 111 to an intermediatepoint P_(i) and then a second angle from the intermediate point P_(i) tothe second end 112. FIGS. 4F and 4G show cutting blades 100 with doublecutting edges 109 a and 109 b that extend from a piercing portion 115located between the first and second ends 111 and 112. In FIG. 4F thedouble cutting edges 109 a and 109 b are straight edges, whereas in FIG.4G the double cutting edges 109 a and 109 b are curved. The cuttingelement 108 is optional, and thus the cutting edges 109, 109 a and 109 bshown in FIGS. 4A-4G can be part of the shank 106 as shown in FIGS.4D-4G or the cutting element 108 attached to the shank 106 as shown inFIGS. 4A-4C.

FIG. 5 is an isometric view illustrating a cutting machine 500 forforming fiber-cement shake-panels or other fiber-cement products fromcured, low moisture content fiber-cement planks and panels. The cuttingmachine 500 includes a frame 510, a plurality of rollers 512 and belts514 that individually and/or together drive a workpiece through thecutting machine 500, and a cutting assembly 520. The cutting assemblyillustrated in FIG. 5 includes a cross member 522, blade mounts 524projecting from the cross member 522, actuators 526 attached to thecross member 522, and end guides 528 that guide the cross member 522along a straight path S. The cutting assembly 520 can further includepress down rollers 529 that move with the cross member 522 and blademounts 524. The cutting machine 500 can further include an anvil plate530 having a plurality of slots 532 corresponding to the blade mounts524. The blades are not mounted to the blade mounts 524 in theembodiment of the cutting machine 500 illustrated in FIG. 5. Inoperation, the actuators 526 drive the cross member 522 downwardly alongthe straight path S between a raised position and a lowered position.

FIG. 6 is an isometric view illustrating a portion of the cuttingassembly 500 illustrated in FIG. 5 with an embodiment of the blades 100illustrated in FIGS. 4A-C. In the embodiment illustrated in FIG. 6, theblades 100 are mounted to the blade mounts 524 such that the first end111 of the cutting element 108 of one blade and the second end 112 ofthe cutting element 108 of the another blade face in the same direction.As a result, the cutting edges 109 of the two blades project downwardlyin opposite directions along the Y-axis. This configuration of attachingthe blades 100 to the blade mounts 524 causes equal and opposite forcesalong the Y-axis as the blades 100 move through the fiber-cementworkpiece, which inhibits the workpiece from moving along the Y-axisduring the cutting process. This becomes more important with the closetolerances between the cutting element 108 and the slots 532. In otherembodiments, the blades 100 can be attached to the blade mounts 524 suchthat the cutting edges 109 all slope downwardly in the same directionrelative to the Y-axis. In still a different embodiment, blades that arenot adjacent to each other can be mounted in a reverse configurationsimilar to the embodiment illustrated in FIG. 6.

The blades 100 can be attached to the blade mounts 524 using shims toadjust the position of the blades 100 along the X-axis. This allows theblades 100 to be accurately aligned with corresponding slots 532 in theanvil plate 530 within the tight tolerances required to cut thefiber-cement panels and planks in a highly dust-free manner. Moreover,the combination of the holes 103 a and slots 103 b in the head 102 ofeach blade 100 enables the blades 100 to be attached the blade holders524 in either the forward or reversed position relative to the Y-axis.The slots 103 b further allow adjustment along the Y-axis to aligned theends of the blades 100 with the ends of the slots 532 in the anvil plate530.

The blades 100 illustrated in FIG. 6 also provide good, square cornersat the closed or blind end of the slots cut through the workpiece. Byproviding a hard, sharp cutting element 108 that can withstand theabrasiveness of cured fiber-cement, the closed end of the slots can havehighly squared corners. This improves the appearance of the slots andappears to reduce the particles or dust that remain on the workpieceafter passing through the cutting machine.

From the foregoing, it will be appreciated that specific embodiments ofthe invention have been described herein for purposes of illustration,but that various modifications may be made without deviating from thespirit and scope of the invention. For example, although the blades andcutting assemblies described above are very well suited for cuttingslots in cured, low moisture fiber-cement panels, they can also be usedto form slots in uncured or partially cured pieces of fiber-cement thathave higher moisture content. Accordingly, the invention is not limitedexcept as by the appended claims.

1. A cutting blade for cutting slots in cured fiber-cement panels havinga low moisture content, comprising: a head configured to be attached toa blade mount; a shank projecting downwardly relative to the head, theshank having an inclined edge; and a cutting edge extending at an angleof approximately 83.5° to 85° relative to an axis parallel to a straightpath along which the blade moves to cut the slots.
 2. The cutting bladeof claim 1 wherein the cutting blade further comprises a hardenedcutting element attached to a lower portion of the shank, and thecutting edge is a lower edge of the cutting element.
 3. The cuttingblade of claim 1 wherein cutting element comprises a carbide edge. 4.The cutting blade of claim 1, further comprising a channel between thehead and the shank, wherein the channel is thinner than the shank. 5.The cutting blade of claim 1 wherein the cutting edge has a first end, asecond end, and a piercing portion at the first end.
 6. The cuttingblade of claim 5 wherein the first end is the lowermost end of thecutting edge.
 7. A cutting machine for cutting slots in fiber-cementworkpieces, comprising: an anvil plate having a plurality of slots,wherein individual slots have sidewalls and end walls; a drive systemfor moving a fiber-cement workpiece over the anvil plate along a drivepath; a cross member above the anvil plate, wherein the cross memberextends transverse to the drive path along which the workpiece travels;an actuator coupled to the cross member, wherein the actuator moves thecross member along a straight path between a raised position and alowered position; a plurality of blade mounts along the cross member atlocations corresponding to the slots in the anvil plate; and a pluralityof cutting blades, wherein individual cutting blades comprise a headconfigured to be attached to a corresponding blade mount, a shankprojecting downwardly relative to the head, and a cutting edge extendingat an angle of approximately 83.5° to 85° relative to an axis parallelto the straight path along which the blade moves to cut slots in thefiber-cement workpiece.
 8. The cutting machine of claim 7 wherein oneblade is mounted to a blade mount such that the cutting edge extendsdownwardly in one direction relative to the drive path of the workpieceand another blade is mounted to another blade mount such that thecutting edge extends downwardly in an opposite direction relative to thedrive path of the workpiece.
 9. The cutting machine of claim 7 whereineach cutting blade further comprises a hardened cutting element attachedto a lower portion of the shank, and the cutting edge is a lower edge ofthe cutting element.
 10. The cutting machine of claim 7 wherein eachcutting blade further comprises a cutting element comprising a carbideedge.
 11. The cutting machine of claim 7 wherein each cutting bladefurther comprises a channel between the head and the shank, wherein thechannel is thinner than the shank.
 12. The cutting machine of claim 11wherein a clearance between the end walls of each slot in the anvilplate and ends of corresponding cutting edges is approximately0.005-0.015 inch.
 13. The cutting machine of claim 11 wherein aclearance between the end walls of each slot in the anvil plate and endsof corresponding cutting edges is approximately 0.010 inch.
 14. Thecutting machine of claim 11 wherein a clearance between the sidewalls ofeach slot in the anvil plate and sidewalls of corresponding cuttingedges is between 0.008-0.020 inch, exclusive of 0.020 inch.
 15. Thecutting machine of claim 11 wherein a clearance between the sidewalls ofeach slot in the anvil plate and sidewalls of corresponding cuttingedges is approximately 0.017 inch.
 16. The cutting machine of claim 7wherein the cutting edge has a first end, a second end, and a piercingportion at the first end.
 17. The cutting machine of claim 7 wherein thefirst end is the lowermost end of the cutting edge.
 18. A cuttingmachine for cutting slots in fiber-cement workpieces, comprising: ananvil plate having a plurality of slots, wherein individual slots havesidewalls and end walls; a drive system for moving a fiber-cementworkpiece over the anvil plate along a drive path; a cross member abovethe anvil plate, wherein the cross member extends transverse to thedrive path along which the workpiece travels; an actuator coupled to thecross member, wherein the actuator moves the cross member along astraight path between a raised position and a lowered position; aplurality of blade mounts along the cross member at locationscorresponding to the slots in the anvil plate; and a plurality ofcutting blades, wherein individual cutting blades comprise a headconfigured to be attached to a corresponding blade mount, a shankprojecting downwardly relative to the head, and a cutting edge extendingat an angle relative to an axis parallel to the straight path alongwhich the blade moves to cut slots in the fiber-cement workpiece, andwherein the cutting edge has a first end, a second end, and a sharppiercing portion at the lowermost point of the cutting edge.
 19. Thecutting machine of claim 18 wherein the piercing portion is located atthe first end of the cutting edge.
 20. The cutting machine of claim 19wherein the cutting edge extends at an angle of approximately 83.5° toapproximately 85° relative to the axis parallel to the straight pathalong which the cutting blade moves to cut the slots.
 21. The cuttingmachine of claim 20 wherein a clearance between the end walls of eachslot in the anvil plate and the first and second ends of each cuttingedge is from approximately 0.005-0.015 inch.
 22. The cutting machine ofclaim 20 wherein a clearance between the end walls of each slot in theanvil plate and the first and second ends of each cutting edge isapproximately 0.010 inch.
 23. The cutting machine of claim 20 wherein aclearance between the sidewalls of each slot in the anvil plate andsidewalls of each cutting edge is between 0.008-0.020 inch, exclusive of0.020 inch.
 24. The cutting machine of claim 20 wherein a clearancebetween the sidewalls of each slot in the anvil plate and sidewalls ofeach edge is approximately 0.017 inch.
 25. A method of cuttingfiber-cement workpieces to form fiber-cement shake panels, comprising:positioning a fiber-cement workpiece over an anvil plate having at leastone slot; and driving a cutting blade along a straight path from araised position to a lowered position to pass a cutting edge of thecutting blade through the workpiece, wherein the cutting edge is astraight edge inclined at an angle relative to the straight cuttingpath.
 26. The method of claim 25 wherein positioning a fiber-cementworkpiece over the anvil further comprises providing a curedfiber-cement workpiece and conveying the cured fiber-cement workpieceuntil a desired portion of the cured fiber-cement workpiece ispositioned over the slot in the anvil plate.
 27. The method of claim 26wherein the cutting edge has a first end, a second end, and a sharppiercing portion at the first end of the cutting edge that defines alowermost point of the cutting edge, and the method further comprisespiercing the cured fiber-cement workpiece with the piercing portion andshearing the fiber-cement workpiece to the second end of the cuttingedge.
 28. The method of claim 26 wherein the cutting edge is inclined atan angle of approximately 83.5° to approximately 85° relative to thestraight path.
 29. The method of claim 28 wherein the cutting edge has afirst end, a second end, and a piercing portion at the first end of thecutting edge that defines a lowermost point of the cutting edge, and themethod further comprises piercing the cured fiber-cement workpiece withthe piercing portion and shearing the fiber-cement workpiece to thesecond end of the cutting edge as the cutting blade travels along thestraight path.
 30. A method of processing fiber-cement workpieces toform fiber-cement shake panels, comprising: positioning a curedfiber-cement workpiece over an anvil plate having at least one slot;driving a cutting blade along a straight, vertical path to pass acutting edge of the cutting blade through the workpiece; and applying acoating to the fiber-cement panels before installing the fiber-cementspanels on a wall.
 31. The method of claim 30 wherein the cutting edgehas a first end, a second end, and a sharp piercing portion at the firstend of the cutting edge that defines a lowermost point of the cuttingedge, and the method further comprises piercing the cured fiber-cementworkpiece with the piercing portion and shearing the fiber-cementworkpiece to the second end of the cutting edge.
 32. The method of claim30 wherein the cutting edge is inclined at an angle of approximately83.5° to approximately 85° relative to the straight, vertical path. 33.The method of claim 32 wherein the cutting edge has a first end, asecond end, and a piercing portion at the first end of the cutting edgethat defines a lowermost point of the cutting edge, and the methodfurther comprises piercing the cured fiber-cement workpiece with thepiercing portion and shearing the fiber-cement workpiece to the secondend of the cutting edge as the cutting blade travels along the straightpath.
 34. The method of claim 30 wherein the coating comprises a paint.35. The method of claim 30 wherein the coating comprises a stain.